The key question enlarging paddy field is how to accurately level the ground. At the present, on account of being restricted by the shortage of old leveling machines and limited level of manual operation, the accuracy of leveling land can not be continually improved after a certain level. For this reason, the type of 1JPY-3.0 laser controlled compositive leveling machine was designed. The article introduced the structure, the work principle, the design of the critical components and its experimental effects. The results of experiment show that the area of the every paddy field was enlarged more than 0.5 hm², the accuracy of leveling was controlled between ±1.5 cm, the irrigation water-saving was about 30% to 45%. By using the machine, and the paddy fields which was leveled can carry out transplanting after irrigated and precipitated four days.